Abrading tool



.May 30, 1944. c. E. ARCHER ABRADING TOOL Filed Feb. 27. 1942 2 Sheets-Sheet l j'nverzior Charks EA rokerfiforne s.

-Ma'y 30, 1944. c; E. ARCHER ABRADING TOOL Filed Feb. 27. 1942 2 Sheets-Sheet 2 Jizuenior C/zarZesEArafier fz orvz g s.

Patented May 30, 1944 I ABRADING TOOL Charles E. Archer, Birmingham, Mich, assignor to Ex-Cell-O Corporation, Detroit, Mich., a corporation of Michigan Application February 27, 1942, Serial No. 432,565

14 Claims.

The invention relates to abrading or lapping tools or the like for removing material by an abrading action from the surfaces of cylindrical bores, and has particular reference to an abrading tool of the type which embodies a mandrel having tapering or wedge surfaces for effecting radial adjustment of a plurality of abrading devices, and in which the abrading devices are arranged to present. in any position of adjust ment active abrading surfaces which are substantially segments of a cylinder and have flat supporting faces related to the axis of the cylindrical segments on an acute angle complemental to the angle of the tapering mandrel surfaces.

One of the objects of the invention is to provide a novel abrading tool of the foregoing character in which the tapering surfaces of the mandrel are entirely flat and free of upstanding ribs and other projections, so that the surfaces may be easily and economically machined or ground.

Another object is to provide an abrading tool of the foregoing character having a new and improved tapered mandrel which is formed in spaced relation to the small end with a longitudinal medial guide slot opening therethrough to the diametrically opposed tapering surfaces and adapted for interfitting slidable engagement with ribs on the abrading devices.

A further object is to provide an abrading tool of the foregoing character comprising a flat supporting holder having ribs on opposite side faces inclined to the plane thereof, the rib on one side face being slidably guided in the supporting mandrel, and the rib on the other side face interfitting with an abrading element.

Other objects and advantages will become apparent as the description proceeds.

Fi ure 1 is a side elevational view of an abrading tool embodying the features of my invention.

Fig. 2 is a longitudinal sectional view of the tool.

Fig. 3 is an end elevatmnal view.

Fig. 44s a transverse vertical sectional view taken substantially along line 4-4 of Fig. 2.

Figs. 5 and 6 are respectively a perspective view of a shoe and a mandrel forming part of the tool.

Fig. 'I is a side elevational view of an abrading element forming part of the tool.

Fig. 8 is an end elevational view of the abrading element.

While the invention is susceptible of various modifications and alternative constructions, I have shown in the drawings and will herein describe in detail, the preferred embodiment, but

it is to be understood that I do not thereby intend to limit the invention to the specific form disclosed, but intend to cover all modifications and alternative constructions falling within the spirit and scope of the invention as expressed in the appended claims.

In the embodiment of the invention that has been selected for illustrative purposes, the numeral I generally designates a tool support in the nature of a chuck, which drivingly receives one end of a mandrel 2 having abrading devices 3 operatively associated with the free or outer end thereof. The mandrel 2 extends coaxially into a driven spindle 4 to which it is connected for joint rotation and independent axial adjustment. An annular clamping member or nose 5 is threaded onto the outer end of the spindle 4, and is formed with an inner peripheral end flange 6. A bearing sleeve 5 is slidable on the mandrel 2 and has a radial flange t on its inner end arranged to be marginally confined between the end face on the spindle t and the flange 6 on the member 5. A washer 9 is interposed between the end face of the spindle and the flange 6, and, as will be presently described, the assembly is employed to secure the abrading elements 3 in position with respect to the mandrel 2, and for longitudinal adjustment relative thereto.

The mandrel (see Figs. 1 to 4 and 6) in the preferred form consists of an elongated circular rod connected at the inner end by means (not shown) to the spindle 2 for rotation therewith. The outer end portion of the mandrel 2 has oppositely disposed tapering wedge surfaces lll which slope gently and uniformly to a relatively thin diametrical end H. The surfaces are inclined oppositely, but in the same degree relative to the axis of rotation so as to constitute the outer end portion of the mandrel 2 a plain twosided wedge member. It will be seen that the tapering or wedge surfaces In increase progressively in width toward the outer end I l, and that the contiguous longitudinal side edges thereof intersect with and are joined by intermediate cylindrical segments l2 decreasing in width toward the outer end.

Since the mandrel 2 is subjected in use to wear, and must be sufficiently strong to resist appreciable deformation and to transmit a positive driving torque to the abrading devices 3, it is made of a suitable material having the desired hardness and wear resisting characteristics. To obtain a correct form, the tapering or wedge surfaces It are accurately ground after hardening. One of the features of the present invention is to provide a mandrel slidably keyed for joint rotary drive to the abrading devices 3, and at the same time free from upstanding ribs or other projections which, if present, would render grinding of the surfaces l more ditficult and costly. Consequently, the tapering or wedge surfaces H] are fiat or planar in form entirely across their width, and the mandrel 2 is formed with a longitudinal medial guide slot I3 for interfitting engagement with the abrading devices 3. So as not to impair the strength of the thin outer end portion of the mandrel 2, the slot I3 is formed in and opens through only the thick inner end portion in longitudinally spaced relation to the end edge H. The slot l3 opens medially to both of the opposed tapering or wedge surfaces l0, and preferably has flat parallel sides.

The slot I3 is in longitudinal alinement with and in effect a continuation of two diametrically spaced longitudinal grooves i4 formed in and extending along the cylindrical shank of the mandrel 2. These grooves M are adapted to receive control members for anchoring the abrading devices 3.

Each abrading device .3 includes an abrading element l5 (see Figs. 7 and 8) having an active face it of sectional cylindrical contour and an opposed flat mounting face H, and an elongated holder or supporting shoe 88 attached as by means of a suitable adhesive to the mounting face ll. 7

The active face it of the abrading element 65 is formed on a radius somewhat greater than that of the mandrel 2 so that the side edges of the element will project beyond the corresponding edges of the tapering or wedge surfaces ill. The opposite or mounting face I! is preferably defined by the plane of a chord of a cylinder, which plane is angularly related to the axis of the cylindrical surface i6 at an acute angle com-- plemental to the angle of the tapering mandrel surface it). Consequently, the resulting body of the abrasive element I5 is a secantial segment of a cylinder tapering gradually and uniformly from end to end in width and inthickness. The width of the fiat inclined face H at the larger end is preferably only slightly less than the diameter of the cylinder, so that the active :face it has a substantially large peripheral area.

The fiat face I! is traversed longitudinally throughout the large end portion by a medial groove l9 which is substantially narrower than the face and which is of uniform width and of progressively increasing depth from the inner to the outer end. The abrading element I5 may be made of any suitable material, such for example as finely divided bonded abrasive, and in such an element, the groove I9 is preferably of square or rectangular cross section to avoid undue weakening of the element. As shown, the root of said groove I9 is substantially parallel to the axis of curvature of the face H5.

The holder or supporting shoe l8, in its preferred form, comprises a flat plate 20 which is somewhat longer than the abrading element l5, and which is shaped to taper uniformly from one end to the other in accordance with the taper of the fiat face I! of the element. The varying width dimensions of the plate 20 are slightly less than those of corresponding parts of the abrading element face Il so that when the element and plate are appropriately secured together in face-to-face abutment, with the wider dimensions substantially coinciding, the side margins of the abrading element will project beyond or overhang the margins of the plate (see Figs. 2 and 3). Thus, onlythe active face it on the abrading element l5 can ever contact the surface of the work.

The plate 20 may be fashioned conveniently of thin gauge sheet metal. The outer or wide half-end portion is formed on one side face with a longitudinal central or medial upstanding rib 2| pressed out of the plane of the plate and inclined thereto. The rib 2! is uniform in width and rectangular in cross section throughout its length, and is dimensioned to interfit snugly and to provide an interlock with the groove I9 in the thick outer end portion of the abrading element 56. Similarly, the narrow or inner half end portion of the plate 20 is formed on the other side face with a longitudinal medial rib 22 pressed oppositely to the rib 2! out of the plane of the plate and inclined thereto. This rib 22 is also uniform in width and rectangular in cross section throughout its length, and increases progressively in height toward the inner end of the plate, and is dimensioned to interfit snugly and to provide a driving interlock with the sides of the slot l3 in the mandrel 2.

It will be seen that the two ribs 2i and 22 project respectively from oppositely side faces of the plate 20 and along opposite half-end per-- tions thereof. The two ribs are in longitudinal alinement and, in efiect, jointly constitute a single rib relatively inclined to and extending through the plane of the plate 20 on its longitudinal medial axis. By the foregoing arrangement, the outermost rib 2i affords a driving interlock between the plate 28 and the abrading element I5 in the large end portion of the element where there is ample stock to accommodate the depth of the groove 09 without impairing the life or strength of the element. The inner end portion of the abrading element 55, which is relatively narrow and thin, is not-traversed by the groove H9. The other depending rib 22 slidably interfits with the slot 5 3 at a point spaced from the thin end ll of the mandrel 2, thereby providing a positive driving connection where there is suflicient thickness to receive the rib and without impairing the strength of the outer end of the mandrel.

Each of the ribs 22 projects inwardly from one side face of the plate 20 toward the axis of the mandrel 2 and defines a groove 23 opening to the opposite outer side face of the plate and in registration with the associated' groove M in the mandrel. An adjusting element, in the form of a thin elongated rod or wire 26, is secured at one end in the groove 23 to the plate 20 and extends slidably through the groove i4. Preferably, the wire 24 is dimensioned to fit snugly in the groove H. The free end of the wire is bent to provide a right angular end portion 25 which forms the means for securing the abrading device 3 to the tool support I. More particularly, the bent end portion of each wire'24 extends through the sleeve I and is clamped by means of the member 5 against movement endwise of the mandrel 2 between the flange 8 and the washer 9.

I In operation, and assuming the abrading devices 3 are assembled on the tool support l and the mandrel 2, the minimum diameter of the cylindrical active faces l8 of the abrading elements I5 is obtained by axial retraction of the mandrel. This adjustment is utilized to permit insertion of the tool into the bore of the work. The abrading devices 3 are maintained in preciselongitudinal relation to the tapering mandrel surfaces H] so that the operator needs only to make certain of proper engagement between the ribs 22 and the slot l3 as he effects insertion of the tool into the bore of the work. The abrading devices 3 are adjusted to increase the effective cutting diameter by outward axial movement of the mandrel 2, in the course of which adjustment the slot [3 will move along but remain in operative engagement with the ribs 22.

I claim as my invention:

1. An abrading tool comprising, in combination, an elongated rod having an end portion tapering gradually and uniformly from opposite sides to a thin end edge, each of the tapering sides being planar in form',said rod being formed with a guide slot opening therethrough medially to the opposed tapering sides and spaced from said end edge, and having a groove in each side extending longitudinally in endwise alinement with and opening to one end of said slot, a lapping device for each of said tapering sides, each of said lapping devices having a longitudinal medial rib extending only through a portion of its length and slidably engaging in said slot, elongated means extending endwise from each of said devices and receivable in the associated groove in said rod, and means for anchoring said elongated means against movement while permitting relative axial movement of said elongated rod.

2. An abrading device for an abrading tool comprising, in combination, an elongated flat sheet metal plate tapering gradually in width from one end to the other end and having a rib pressed out of the plane of said plate on one side and along one end portion, and a rib pressed out of the plane of said plate at the other side and along the other end portion, an abrading element having a flat face for, abutment with said plate and having a groove to receive said first mentioned plate rib, the longitudinal edges of said element extending beyond the corresponding m'argins of said plate, a mandrel having a planar wedge surface adapted for engagement by said plate and being formed with a guide slot spaced from the end and arranged to slidoperative association.

3. An abrading device for an abrading tool comprising, in combination, a mandrel having a free end portion which is formed on two opposed sides respectively with plane surfaces inclined oppositely and at the same degree toward the axis to provide a wedge-shaped body tapering gradually and uniformly to a thin end edge, said body being formed inwardly of said end edge with a longitudinal medial guide slot opening therethrough to said inclined surfaces, two fiat elongated plates slidably disposed respectively on said surfaces and each having a longitudinal medial rib extending throughout one end portion and slidably engaging in said slot, each plate also having a longitudinal medial rib on and extending along the outer face thereof, and an abrading element attached to the outer face of each of said plates and having a longitudinal medial groove interfitting with said last mentioned rib, said abrading element comprising an elongated body shaped as a secantial segment of a cylinder with the plane of the secant chord lying at an acute angle to the axis of the cylindrical surface complemental to the angle of said inclined surface.

4. A mandrel for an abrading tool comprising an elongated rod having an outer end portion tapering gradually and uniformly from diametrically opposed sides to a relatively thin diametrical edge, each of the tapering sides of said rod defining a plane fiat tapering or wedge surface, said tapered end portion being formed in spaced relation to said edge with a longitudinal guide slot closed at the ends and opening therethrough to both of the wedge surfaces intermediate the side edges thereof, said slot at said opposed sides being adapted slidably to receive interfitting guide ribs on abrading elements adapted for sliding engagement respectively with said wedge surfaces.

5. A mandrel for an abrading tool comprising an elongated cylindrical rod having a free outer end portion which is formed on two diametrically opposed sides respectively with plane surfaces inclined oppositely and at the same degree toward the axis of said rod to provide a wedge-shaped body tapering gradually and uniformly to a thin diametrical end edge, said body being formed inwardly of said thin end edge with a narrow longitudinal guide slot opening therethrough medially to said inclined surfaces, said slot being closed at opposite ends and having fiat parallel sides, the cylindrical portion of said rod inwardly of said slot being formed in the periphery with two diametrically opposite flat-sided longitudinal grooves in alinement with and opening at their outer ends to the inner end of said guide slot and being of the same widthas said slot, said slot at said opposed sides being adapted slidably to receive interfitting guide ribs on abrading elements adapted for sliding engagement respectively with said surfaces.

6. A mandrel for an abrading tool comprising an elongated rod having a free outer end portion which is formed on two opposed sides respectively with plane surfaces inclined oppositely and at the same degree toward the axis of said rod to provide a wedge-shaped body tapering gradually and uniformly to a thin end edge, said body being formed inwardly of said thin end edge with a narrow longitudinal guide slot opening therethrough to said inclined surfaces, the portion of said rod inwardly of said slot being formed with two opposite longitudinal grooves in alinement with and opening at their outer ends to the inner end of said guide slot, said slot at said opposed sides being adapted slidably to receive interfitting guide ribs on abrading elements adapted for sliding engagement respectively with said inclined surfaces.

7. A holder for the abrading element of an abrading tool compriisng a thin flat plate tapering gently and symmetrically in width from end to end and formed with a hollow longitudinal medial rib pressed out of the plane of said plate" and inclined to and extending through the plane of said plate, one end portion of said rib projecting from one side face of said plate and the other end portion of said rib projecting from the other side face of said plate.

8. A holder for the abrading element of an abrading tool comprising an elongated plate having flat side marginal portions in substantially the same plane and having am intermediate 1ongitudinally extending portion providing only along one end portion a medial rib projecting to one side of said plane and tapered in height to merge at its inner end into said plane and only along the other end portion a medial" rib projectabrading tool comprising an elongated plate having flat side marginal portions in substantially the same plane andhaving an intermediate longitudinally extending portion providing along one end portion a medial rib projecting to one side of said plane and along the other end portion a medial rib projecting to the other side of said plane, said ribs being in longitudinal alinement and being of uniform width and increasing height from their inner ends toward their outer ends so as to be inclined to said plane.

11. An abrading element for an abrading tool comprising a body shaped as a secantial segment of a cylinder, the plane of the secant chord being angular with respect to the axis of curvature of the cylindrical surface to provide a body tapering in width and thickness from end to end, the plane face of the body intersecting the cylindrical surface to define sharp side edges and being traversed in the large end portion by a longitudinal medial groove of uniform width and increasing gradually in depth from a point substantially midway of the ends of the body where it merges into the plane face to the large end thereof, the plane face of said body in the small end portion being uninterrupted;

12. An abrading element for an abrading tool comprising a body shaped as a secantial segment of a cylinder, the plane of the secant chord being angular with respect to the axis of curvature of the cylindrical surface to provide a body tapering.

in width and thickness from end to end, the plane face of the body in the large end portion being longitudinally traversed by a medial groove increasing gradually in depth from a point substantially midway of the ends of the body to the large end thereof, the plane face of said body in the small end portion being uninterrupted by said groove.

13. An abrading element for an abrading tool comprising a body shaped as a secantial segment of a cylinder, the plane of the secant chord being angular with respect to the axis of curvature of the cylindrical surface to provide a body tapering in width and thickness substantially from end to end, the plane face of the body in the large end portion being longitudinally traversed by a groove from a point starting intermediate the ends of the body to the large end thereof, the root of said groove being substantially parallel to said axis.

14. An abrading device for an abrading tool comprising, in combination, an elongated plate tapering gradually in width from one end to the other end and having a rib projecting out of the plane of said plate on one side and along one end portion, and a rib projecting out of the plane of said plate at the other side and along the other end portion, an abrading element having a face for abutment with said plate and having a groove to receive said first mentioned plate rib, the longitudinal edges of said element extending beyond the corresponding margins of said plate, a' mandrel having a wedge surface adapted for engagement by said plate and being formed with a guide slot and arranged to slidably receive said last mentioned rib, and means for supporting said mandrel and said plate in operative association.

, CHARLES E. ARCHER. 

